Viscosity Classification of Lubricants For Axles And Manual Transmissions
The viscosity of automotive manual transmission oils is described by SAE (Society of Automotive Engineers) viscosity grades. SAE J306 standards set: the temperature of viscosity measurement, viscosity limits and the distribution of viscosity grades. Oils for which viscosity limits are set in the cold state have an additional letter W (Winter). Seasonal and multigrade gear oils are available. Modern multistage gearboxes require all-season oils with a wide viscosity range of SAE 75W-90 or SAE 75W-80. For hypoid main gears, viscosity grades from SAE 75W to SAE 85W-140 are recommended.
Viscosity Grades SAE J306
| SAE Grade |
Maximum temperature, оС at viscosity 150000 mPa·s | Kinematic viscosity, mm2/s at 100 оС | Kinematic viscosity, mm2/s at 100 оС after 20 hours KRL test (CRC L-45-T-93), min | |
| min | max | |||
| 70W | -55 | 4,1 | – | 4,1 |
| 75W | -40 | 4,1 | – | 4,1 |
| 80W | -26 | 7,0 | – | 7,0 |
| 85W | -12 | 11,0 | – | 11,0 |
| 80 | 7,0 | <11,0 | 7,0 | |
| 85 | 11,0 | <13,5 | 11,0 | |
| 90 | 13,5 | <18,5 | 13,5 | |
| 110 | 18,5 | <24,0 | 18,5 | |
| 140 | 24,0 | <32,5 | 24,0 | |
| 190 | 32,5 | <41,0 | 32,5 | |
| 250 | 41,0 | – | 41,0 | |